JPS6445125A - Method and apparatus for cleaning semiconductor wafer - Google Patents

Abstract

PURPOSE:To make it possible to remove native SiO2 completely, by bringing a semiconductor wafer and supercritical gas into contact, introducing reactive gas into the supercritical gas, and bringing the semiconductor wafer and the supercritical gas into contact without introducing the reactive gas. CONSTITUTION:A semiconductor wafer is exposed to supercritical gas. The surface of the semiconductor wafer, pattern grooves and minute parts in holes are brought into contact with the gas and cleaned. Then, native SiO2 is removed as follows: reactive gas such as HF and HCl, which dissolves those oxides, is mixed with the supercritical gas; the mixed gas is brought into contact with the semiconductor wafer; and the wafer is cleaned. The introduction of the HF gas and the addition of H2O are finally stopped. A step, by which the wafer is brought into contact with only the supercritical gas, is added. Thus moisture, which is attached to the wafer, is dissolved with the supercritical gas, taken out and discharged. Then the dry wafer is obtained and sent to the next manufacturing step. In this way, the native SiO2 can be effectively removed.